PersonalGenBank is a database software maintaining sequences and sequence
information in GenBank-format. Generally, the user downloads a large chunk of sequences from
GenBank to the local computer and then imports these sequences into PersonalGenBank. Sequence
entries (the accession number) that are already present in the local PersonalGenBank-database
are not imported except if the data deviates from existing data! In this case the old data is
not overwritten but a new record is added to the database. The old record is marked as 'obsolete'
in a special database field whereas the new record is marked as 'updated' plus a list of the
deviating fields. This enables the user to quickly find updated records and to compare changes
to previous data.